Bounder: Dometic fridge issues.

[Shadowrip]

How does the AC and DC side of a three way ref work? Do they all heat up the amonia the same way the propane does?

[Old-Biscuit]

Originally Posted by Shadowrip

How does the AC and DC side of a three way ref work? Do they all heat up the amonia the same way the propane does?

AC....120VAC Heater Element 250W - 450W depending on size of fridge. Generates roughly same 'transferred' heat as LP Flame transfers to boiler section to turn liquid ammonia solution into ammonia vapor

DC....12VDC Heater Element 175W - 195W depending on size of fridge. Generates just enough heat transferred to MAINTAIN a COLD fridge. Not to be used to initially cool a fridge down, Not to be used while stationary w/o means of maintaining/charging batteries due to high DC demand
Idea is to use it while in transit.

DC is an 'option' vs using LP while in transit but NOT intended for boondocking

3-way fridges are not in high production anymore

[Shadowrip]

Originally Posted by Old-Biscuit

AC....120VAC Heater Element 250W - 450W depending on size of fridge. Generates roughly same 'transferred' heat as LP Flame transfers to boiler section to turn liquid ammonia solution into ammonia vapor

DC....12VDC Heater Element 175W - 195W depending on size of fridge. Generates just enough heat transferred to MAINTAIN a COLD fridge. Not to be used to initially cool a fridge down, Not to be used while stationary w/o means of maintaining/charging batteries due to high DC demand
Idea is to use it while in transit.

DC is an 'option' vs using LP while in transit but NOT intended for boondocking

3-way fridges are not in high production anymore

Interesting!
Explains why DC was sucking my battery's dry quickly!

[1972VWbus]

One of the following inside the fridge does wonders...

https://www.amazon.com/Beech-Lane-Mu...14&sr=8-5&th=1

[1ramblingman]

Well...So I was trying to reach the thermostat through the roof vent and dropped one of the wires and it disappeared down the cavity. Grabbed my phone to try and get a picture of how far down it was, snagged my hand on something sharp and my phone fell down the gap between the wall and the flue. Needless to say, I had to pull the fridge. haha That turned out to be a good thing. Gave me a good opportunity to clean the flue tube and when I pulled the baffle out, this is what I found. Can't believe it. The end of it is melted away. Needless to say, going to be replacing it. I was able to verify the fans worked directly off 12v source but while I'm in this nightmare, going to go ahead and replace them along with the thermostat which I'm sure is bad because there is 12v going to it. Any recommended fan upgrades or is sticking with the factory fans the best choice? I was also able to completely clean everything and get all the pine needles out of and off of everything. I can't wait for this project to be over! haha

[Fridge Defend]

Originally Posted by 1ramblingman

Attachment 366993

Any recommended fan upgrades or is sticking with the factory fans the best choice? I was also able to completely clean everything and get all the pine needles out of and off of everything. I can't wait for this project to be over! haha

We offer a complete blower package and fan controller that includes defrost blowers that go within fridge. This design is so you do not take up space inside the fridge with a fan while replacing batteries to keep it running.

You do not want fans to run within the fridge full time, it results in the cooling unit cycling too often. Our controller only runs the fans when refrigerant is being produced.

The plus, you solve the problem of boiler overheating and killing your fridge this way.

Hope this helps, Paul

[Old-Biscuit]

After cleaning up that gunk blocking the flue you achieved really good temps freezer/food compartment





Which surprises me with the condition the flue baffle is in........LOL




Clean burner assembly/clean flue/new flue baffle & fans that run.......
You should be able to hang meat in the food compartment

Good Job!

[1ramblingman]

PM sent about the blower package. I'm amazed the temps that were reached too but more amazed this thing didn't burn to the ground! Will be good to go for a while once this is all done. There's been a lot of time spent on getting our new coach in tip top shape. Even rebuilding the vacuflush vacuum generator now while I'm waiting on fridge parts. Can't wait until this is all done! The coach is a 2012 and only has 11k miles on it and the previous owner spent a lot of money upgrading to the front and rear sway bars, steering stabilizer, 400 watts of solar panels, brand new Toyo tires and the audio system just to name a few. Evidentaly he didn't spend much time maintaining the fridge. lol Oh, and none of the seating "leather" is pealing! In perfect shape! lol

[SavnTheWales]

This thread reminded me I needed to post a video in my queue. This should cover a lot of questions on the Dometic RM1350.

https://www.youtube.com/watch?v=fHCvrTYhu0s

You want the factory fans, but good luck finding them. The factory fans have way more CFM than ANY fan you find on Amazon.

The factory fan is: on my 2012 Bounder 35k
Sunon PF92251B1-000U-A99
92x92x25mm
12v
360ma
4.32w
4500rpm
75cfm
.35 static pressure
46db noise
Rotation cw

I had one fan fail (there are 2 fans), so I ended up adding 2 fans in its place to get back to the cfm. So now I have 3 fans.

I also wired a switch so I could manually override the temp switch. It’s easy, see video.

I hear my fans run, but they normally only run for a minute or two as the temps drop quickly. Maybe that will change when it gets 100 degrees outside.

Also my relay was bad, so check that, it’s needed to run fans.

[Fridge Defend]

Originally Posted by SavnTheWales

You want the factory fans, but good luck finding them. The factory fans have way more CFM than ANY fan you find on Amazon.

The factory fan is: on my 2012 Bounder 35k
Sunon PF92251B1-000U-A99
92x92x25mm
12v
360ma
4.32w
4500rpm
75cfm
.35 static pressure
46db noise
Rotation cw

A word of caution, the rating on a muffing fan (computer fan) is with no back pressure. Do you know how much noise a 75cfm fan would make?

These fans make a ton of noise, you want high static pressure and constant flow like a blower provides. 25cfm will move all the air in the cooling unit every minute.

[1ramblingman]

Ended up pulling the fridge. What a not so fun experience. Was out for several days while I was waiting for the flue baffle. Finally showed up but was 39" instead of 40" so I took the baffle and attached it to the original rod to get the right length to maintain the required distance from the burner to the baffle. Glad I checked and didn't assume the length was right on the rod and the baffle length was to spec. All that said. Put it back together with a new thermal switch for the fans and all is working as it should now.
61 degrees start temp in freezer and fridge, 60 degrees ambient
On LP
1 hr freezer 48 fridge 60
2 hr freezer 23 fridge 56
3 hr freezer 11 fridge 48
4 hr freezer 06 fridge 42
5 hr freezer 03 fridge 38
5.5 hr freezer 1.3 fridge 34 and shut off.
Fans came on a couple days later when the ambient temp reached 80.
Going to order Fridge Defend and will update once installed and compare numbers. Thanks so much to everyone for all the help.

[Old-Biscuit]

It's amazing how well a heat pump can cool fridge down when working as designed

KUDOs to you for hanging in there and following it thru to the end.

That's for the update and resolution!

[Fridge Defend]

Originally Posted by 1ramblingman

Ended up pulling the fridge. What a not so fun experience. Was out for several days while I was waiting for the flue baffle. Finally showed up but was 39" instead of 40" so I took the baffle and attached it to the original rod to get the right length to maintain the required distance from the burner to the baffle. Glad I checked and didn't assume the length was right on the rod and the baffle length was to spec. All that said. Put it back together with a new thermal switch for the fans and all is working as it should now.
61 degrees start temp in freezer and fridge, 60 degrees ambient
On LP
1 hr freezer 48 fridge 60
2 hr freezer 23 fridge 56
3 hr freezer 11 fridge 48
4 hr freezer 06 fridge 42
5 hr freezer 03 fridge 38
5.5 hr freezer 1.3 fridge 34 and shut off.
Fans came on a couple days later when the ambient temp reached 80.
Going to order Fridge Defend and will update once installed and compare numbers. Thanks so much to everyone for all the help.

Good work!

You hit on something that is not often thought about, the incorrect baffle/ defuser being put in

FYI: To check if the baffle is correct, hold it where the stop holds it in the flue. Look into the boiler assembly, the spiral should be just where the welds for the flue tube are, or if you cannot see these welds, where the heater pocket welds are.

Thanks

[Old-Biscuit]

Originally Posted by Fridge Defend

Good work!

You hit on something that is not often thought about, the incorrect baffle/ defuser being put in

FYI: To check if the baffle is correct, hold it where the stop holds it in the flue. Look into the boiler assembly, the spiral should be just where the welds for the flue tube are, or if you cannot see these welds, where the heater pocket welds are.

Thanks

Or check the manual for proper length/height
Dometic and Norcold list flue baffle specs